Dispensing devices for dispensing a foamable product from a container are known in the art. In one example, the dispensing device is disposed on top of a pressurized container containing a foamable product. The dispensing device comprises a flow passage that is coupled at one end to a discharge valve of the pressurized container. A discharge outlet is provided at the other end of the flow passage. To dispense the foamable product, the user presses an actuator part of the dispensing device. This opens the discharge valve of the container. Product then flows into the flow passage and is discharged through the discharge outlet. This discharge occurring from the discharge outlet is driven by the flow of foamable product entering the flow passage from the container, propelled by the vapor pressure of the propellant in the container. The foamable product also expands into a foam within the flow passage as it is being dispensed, such that the volumetric flow rate at the discharge outlet is greater than that at the discharge valve of the container.
After a desired amount of foam has been dispensed, the user releases the actuator, closing the discharge valve of the container, and thereby shutting off the supply of product to the flow passage. In this way, the user can control the amount of foam that is dispensed according to the length of time for which the actuator is held pressed.